1. Technical Field
The present invention relates to a projector configured to project an image light.
2. Related Art
In the related art, a projector configured to form an image light by modulating a luminous flux emitted from a light source according to image data, and project the image light onto a screen or the like. The projector is used in various applications such as presentations in companies or appreciation of movies in the family. In order to improve a contrast of an image, a technique to control amount of light of the luminous flux emitted from the light source using a light amount control device is proposed (see JP-A-2007-71913).
The light amount control device disclosed in JP-A-2007-71913 includes a rectangular tubular shaped fixing member, a supporting shaft (axis of rotation) attached to the fixing member, a shielding member configured to partly shield the luminous flux emitted from the light source, a drive gear, a motor having a pinion, and so on, and is arranged in an optical component housing.
The shielding member includes the drive gear attached at one end, and the drive gear engages the pinion, and is rotatably supported by the supporting shaft. The other end of the shielding member is rotatably supported by the fixing member. When the motor is driven, in the light amount control device, the drive gear is rotated, the position of the shielding member is changed to partly shield the luminous flux from the light source according to the position of the shielding member, so that the amount of light is controlled.
JP-A-2007-71913 is an example of related art.
However, the light amount control device disclosed in JP-A-2007-71913 has a probability such that when the temperature rises in association with the shielding of the luminous flux by the shielding member, heat of the shielding member is transferred to the drive gear attached to the shielding member, and hence the drive gear is thermally deformed. When the drive gear is deformed, the rotation may become unstable, or the rotation may be disabled. Consequently, the shielding member cannot be changed in position with high degree of accuracy, so that adequate modulation of the amount of light may not be achieved by the light amount control device.